In order to reduce transport costs, operators of legacy TDM networks may wish to transport TDM traffic over IP/MPLS core networks. Circuit Emulation Service over Packet (CESOP) Pseudowire (PW) allows such operators to do so. A Circuit Emulation Service (CES) device is used as an edge device between the legacy network and the IP/MPLS network. The CES device accepts synchronized cells, such as over a T1 line in TDMA format, encapsulates and packetizes the data, and sends the packets over a packet network such as an IP/MPLS network. At the far end of the packet network, another CES device converts the packet data back into synchronized data for recognition and transmission through the synchronized data network.
Zarlink™ produces a CES device, the Zarlink ZL50110/1/4 chip (“the Zarlink chip”). The Zarlink chip converts synchronized data to packet data. However, the encapsulation is only to layer 2 and is very basic, because CESoP processing is very processor intensive. The Zarlink chip provides no quality of service (QoS) monitoring, buffering, or customer billing.
Marvell™ produces an IP/MPLS packet processor, the Marvell MX-610/5 IP/MPLS chip (“the Marvell chip”). The Marvell chip is designed to tie packets to a customer, and thereby provide QoS monitoring, billing, buffering, and other customer specific features to packet traffic. However, the Marvell chip acts on Ethernet traffic or IP/MPLS traffic. If the Marvell chip receives a CESoP packet, it will discard the packet as junk.
A method of combining packet processing with packet-to-synchronized conversion would allow operators of legacy synchronized networks, such as TDM networks, to carry traffic over packet networks using CESoP while still tying traffic to customers, allowing the operator to offer customer-specific features.